1. Field of the Invention
The present invention relates to a blocking device for a nail gun for preventing a shooting action of the nail gun when there are no nails in the nail gun, and more particularly to a technology to detect whether there is any nail in the nail gun so as to hold or release a safety bar of the nail gun accordingly.
2. Description of Related Art
In most nail guns, there is generally a blocking device configured for automatically detecting for a “no nail” status when all nails, which are aligned in rows in a nail cartridge of the nail gun, are depleted during an operation of the nail gun and when such a status is detected disabling a trigger of the nail gun to drive a nail hitting bar to make a hitting movement so as to inform an operator to fill in nails to the nail gun.
A relatively advanced technology, as disclosed by Taiwan patent M269156, provides a blocking device for a nail gun for preventing a shooting action when the nail gun is in the “no nail” status as described above. A touch member is disposed on a nail pusher of the nail gun. An end groove opening outwards is formed on a side of a nail cartridge of the nail gun. A brake member is disposed in the end groove configured for receiving push from the touch member and rotating accordingly. A spring board configured for pushing the brake member is disposed on an outer wall of a side of the nail cartridge that has the brake member. By this means, when the last nail in the nail cartridge is pushed into a nail hitting groove and being shot, the touch member pushes the brake member to rotate slopingly out of the nail cartage so as to hold a safety bar of the nail gun, prevent the nail gun from continuing with a shooting action and inform an operator to fill in nails to the nail gun.
However, when the brake member rotates slopingly out of the nail cartridge as described above, the safety bar can only touch a sloping cross-section of the brake member, which may generate a sloping component force affecting the brake member. As a result, the braking member may be easily pushed by the safety bar back to a non working position, which hence reduces the accuracy and the reliability of the blocking device in preventing the nail gun from shooting in the “no nail” status. In addition, the spring board disposed on the outer wall of the nail cartridge is exposed outside and hence easy to be contaminated by outside dirt and dusts. The spring board being configured for pushing the brake member is only a thin slice so that the elastic force it can provide to bring the brake member back to an original position after the brake member rotates outwards may be limited and even insufficient. An elastic fatigue failure may happen to the spring board as well. Hence it is desired to provide a blocking device for a nail gun that overcomes the above-mentioned problems.